1. Field of the Invention
The present invention relates to a lighting apparatus.
2. Discussion of the Related Art
The lighting industry has played a key role in advance in human culture and has been closely connected to the advancement of the human race since the dawn of time.
Recently, advances in the lighting industry have progressed at a vigorous pace and numerous studies related to light sources, light emitting methods, driving methods and efficiency enhancement have been conducted.
Examples of current light sources used in lighting apparatuses include incandescent bulbs, fluorescent lamps and discharge lamps. These light sources have been used for a variety of purposes, such as domestic, industrial, and outdoor purposes.
However, light sources operating based upon electrical resistance, such as incandescent bulbs, etc., have problems of low efficiency and high heat loss, discharge lamps are expensive and exhibit poor energy efficiency, and fluorescent lamps have a problem of environmental pollution due to use of mercury.
To solve disadvantages of these light sources, interest in light emitting diodes, which have a great number of advantages, such as high efficiency and realization of various colors and designs, etc., is increasing.
In particular, demand for a surface light source having more uniform optical characteristics than point/linear light sources is increasing.